An arrangement of the above-mentioned kind for a steerable rigid axle on a tractor is the subject of a previous patent document D.E. 38 34 693. The rigid axle arranged in front of the engine is centrally swingably suspended in a transverse wheel fork, which together with a combined spring and damper element takes care of the suspension of the rigid axle. In one variant, the propeller shaft acting upon the rear side of the rigid axle runs centrally under the engine, which in this modular construction is connected with the flywheel housing and the transmission. In such a standard construction of the tractor using a spring-mounted rigid axle with propeller shaft, problems arise with respect to the construction of the engine oil sump, since the shaft limits considerably the space required for the oil sump. In a further variant, in order to avoid this problem a forked propeller shaft whose sides can laterally bypass the oil sump is used. The side parts running next to the oil sump reduce thereby the free space for the maximum excursion of the steering angle of the wheel which at that time is on the inside of the curve.
From the prospectus entitled "Technisches Konzept, Mercedes-Benz-Allradschlepper" MK 6703.3561.00-00/0287 a tractor with modular construction is known, whose propeller shaft acting upon the rigid axle is eccentrically arranged to bypass the engine oil sump and is supported on a power-drive transmission housing. Such a concept is not suitable for tractors of standard construction, wherein the construction units are connected to each other in a modular design.